Parents who help their children with homework may actually be bringing down their school grades. Other forms of prenatal involvement, including volunteering at school and observing a child's class, also fail to help, according to the most recent study on the topic.
The findings challenge a key principle of modern parenting(养育子女) where schools except them to act as partners in their children's education. Previous generations concentrated on getting children to 
school on time, fed, dressed and ready to learn.
       Kaith Robinson, the author of the study, said, "I really don't know if the public is ready for this but there are some ways parents can be 
involved in their kids' education that leads to declines in their academic performance. One of the things that was consistently negative was
 parents' help with homework." Robinson suggested that may be because parents themselves struggle to understand the task." They may 
either not remember the material their kids are studying now, or in some cases never learnt it themselves, but they're still offering advice."
       Robinson assessed parental involvement performance and found one of the most damaging things a parent could do was to punish their children for poor marks. In general, about 20% of parental involvement was positive, about 45% negative and the rest statistically
 insignificant.
      Common sense suggests it was a good thing for parents to get involved because "children with good academic success do have involved
 parents ", admitted Robinson. But he argued that this did not prove parental involvement was the root cause of that success." A big 
surprise was that Asian-American parents whose kids are doing so well in school hardly involved. They took a more reasonable approach, conveying to their children how success at school could improve their lives."

"Over the years the unthinkable hasbecome thinkable and today we sense we are close to being able to alter humanheredity œ#)." These were the words of David Baltimore of the CaliforniaInstitute of Technology, on December 1st, when he opened a three-day meeting inWashington to discuss the morality and use of human gene editing. Dr Baltimoreis an old hand at these sorts of discussions, for he was also a participant inthe Asilomar conference, in 1975, which brought scientists together to discussa safe way of using the then-new tcchnology of recombinant DNA, and whoserecommendations influenced a generation of biotechnology researchers.

Four decades on, the need for a similarsort of chin-wag has arisen. The InternationalSummit on Human Gene Editing has been held by the national scientific academiesof three countries — America, Britain and China. They are particularlyconcerned about whether gene editing should be used to make heritable changesto the human germ line, something Dr Baltimore described as a deep andtroubling question. Like those of Asilomar, the conclusions of this meetingwill not be binding. But the hope is that, again like Asilomar, a mixture ofcommon sense and peer pressure will create a world in which scientists aretrusted to regulate themselves, rather than having politicians and civilservants do it for them. The meeting is being held against a backdrop of rapidscientific advance, Since 2012 research into a new, easy-to-use editing tool calledCRISPR-Cas9 has blossomed. This technique involves a piece of RNA (a chemicalmessenger, which can be used to recognise a target section of DNA) and anenzyme (酶)called a nuclease that can snip unwanted genes out and paste new ones in.

Public interest was aroused in April,when Chinese scientists announced they had edited genes in non-viable ( 无活力的) humanembryos, and again in November when British researchers said they hadsuccessfully treated a one-year-old girl who had leukaemia ( 白血病),using gene-edited T-cells. T-cells are part of the immune system that attack,among other things, tumour cells. The researchers altered T-cells from ahealthy donor to encourage them to recognise and kill the patient's cancer, tomake them immune to her leukaemia drug, and to ensure they did not attack herhealthy cells.

In another recent development, a firmcalled Edit as Medicine, which is based in Cambridge, Massachusetts, has saidit hopes, in 2017, to start human clinical trials of CRISPR-Cas9 as a treatmentfor a rare genetic form of blindness known as Leber congenital amaurosis (伯氏先天性黑蒙).Though other companies are already testing gene-editing therapies, these employolder, clunkier forms of the technology that seem likely to have lesscommercial potential. Moreover, researchers at the Broad Institute, also inCambridge, said this week that they had made changes to CRISPR-Cas9 whichgreatly reduce the rate of editing errors — one of the main obstacles to thetechnique's medical use.

On the subject of germ-line editing,Eric Lander, the Broad's head, told the meeting it would be useful only in rarecases and said it might be a good idea to "exercise caution? before makingpermanent changes to the gene pool. The need for caution is advice that mightalso be heeded by those pursuing work in animals other than people, and inplants — subjects not being covered by the summit.

    It is often necessary to release a fish, that is, set it free after catching, because it is too small, or you just don't want to take it home to eat. In some cases, releasing fish is a good measure that will help keep fish variety and build their population size. The Department of Game and Inland Fisheries (DGIF) encourages fishermen who practice catch-and-release fishing to use a few simple skills when doing so. The advice provided below will help make sure that the fish you release will survive to bite again another day.

    —When catching a fish, play it quickly and keep the fish in the water as much as possible.

    Don't' use a net in landing the fish and release it quickly to prevent it from dying.

    —Hold the fish gently. Do not put your fingers in its eyes. Don't wipe the scales (鱼鳞) off the fish because it might cause it to develop a disease and reduce its chance of survival.

    —Remove your hook (鱼钩) quickly. If the hook is too deep or hooked in the stomach, cut the line and leave the hook in. The hook left inside will cause no serious problem to the fish.

    —Take good care of the fish by moving it gently in water. Release the fish when it begins to struggle and is able to swim.

    —Do not hold fish in a bucket or some other containers and later decide to release it. If you are going to release a fish, do so right away.

    With a little care and by following the suggestions given above, you can give the released fish a better chance of survival.

Scholastic Art: What is your job?

Jayson Fann: I build human-sized nests all over the world.

SA: Can people sit in your nests?

JF: Yes! People have dinner parties in my nests. They read and relax in them. Some of my nests even have several rooms. My nests are even used as hotel rooms.

SA: How do you make a nest?

JF: First, I make a design for the nest. Then I review the design with my client（客户）. After the design is final, I collect wood and work with a team to build it.

SA: What do you use to make your nests?

JF：I use eucalyptus（按树）wood， which is soft and easy to bend when it is young and freshly cut. But when it dries, it becomes extremely hard. So it holds its shape and can support weight. But the structure's strength also comes from the engineering -- how I weave the wood, and how I join major sections by bolting（用螺栓固定）them together.

SA: What makes a great nest design?

JF: Placement is important. The lines of the branches（树枝） create movement and energy, resulting in a cleaner, simpler background -- such as smooth stone or the sky -- which really fits the nest. For me, it's all about balance.

SA: What skills do you need for your job?

JF: You have to be able to draw and use different artistic tools. But you also have to know how to speak to people -- your clients and the people who work for you.

SA: What inspires you?

IF: I love to see how other artists, like Andy Goldsworthy, take common and natural materials and make something special with them.

SA: What is the best part of your job?

JF: I get to be creative in a way that doesn't harm the environment!

Harry, the first camel to arrive in Australia in 1840, was an unlucky beast. He was imported from the Canary Islands by explorer John Horrocks. On an expedition (探险), Horrocks picked up his gun in order to shoot “a beautiful bird to be added to the collection.” Perhaps Harry was an ecologist —- he lurched (突然倾斜), and the gun discharged, shooting Horrocks in the face.

    Horrocks not surprisingly died of his injuries, and his treatments ordered Harry to be shot. The first importation of a camel into Australia came to naught.

    In 1860, 24 camels arrived in Australia to be part of an expedition by explorers Robert O'Hara Burke and William John Wills. It was an unlucky expedition. The pair made one mistake after another, and ended up eating most of their camels, before starving to death.

    Six years later, more than 100 camels and their Afghan minders, arrived in Australia. This time it succeeded and thousands more camels followed.

    Sir Thomas Elder set up the first camel studs (种畜场) in South Australia, while others were set up in Western Australia. This time the camels bred (繁殖) like wildfire. They were used for working, rather than exploring expeditions.

    The imported Afghan cameleers were just as hardy and vital, leading camel trains across the cruel interior (腹地) of Australia, where few dared to go. The camels carried heavy packs of wool and supplies and opened up the desert areas as none had managed to do before. The train that does this crossing today is called The Ghan, in their honor.

    Motorization put these camel trains out of business, and many camels were turned loose. The camels loved Australia, and multiplied in amazing numbers. What is to be done with them?

    Not surprisingly they have become quite a tourist attraction and you can take a camel ride in the desert as the Afghan cameleers once did. But the fact is that camels create quite a problem in areas where they have taken over, as they damage local vegetation, muscle out native animals competing for food, and create chaos when they wander into settled area.

    A while back I caught a news report on something called couch surfing and the network of trusting souls who make this phenomenon possible. They offer to put up travelers free of charge and help them on their ways. At first, it sounded unbelievable. I mean, inviting strangers into one's home for one or two nights? Give me a break.

    However, I was intrigued. I decided to find it out. The only way to truly learn about this phenomenon was to dive in. So I planned a trip to Finland, a country I've always wanted to explore. I would couch surf at every stop there.

    If ever any anxiety existed when stepping into the unknown, it disappeared when my first host met me at the train station. Ari looked like my idea of a typical Finn: tall and blue-eyed. Finns were also supposed to be famously reserved (寡言少语的). Ari was anything but. He was a live wire, giving me a warm welcome and walking with me to his apartment, where he showed me the sleeper sofa, served me tea, and engaged me in warm conversations. He also handed me a key to come and go as I pleased.

    If this was what couch surfing was all about—trust and friendship—then I had gotten off to a good start. As I boarded my next train to continue my journey, I began to think about this couch-surfing idea. What encouraged these people to open their homes to strangers? I concluded that there was a desire to lend a hand to like-minded folks who might enrich their own lives.

    Seven cities in 14 days. Seven hosts. Seven new friends. If couch surfing taught me anything, it's this: Most people are good and generous. Where will couch surfing take me next? Who knows? But I can't wait to find out.